if you use SqlMetal to generate DataContext classes against an SQL database, you might run into some problems with GridView and deleting a row, when using a LinqDataSource.
this was a very frustrating problem to track down, apparently there is a bug in the LinqDataSource with datetime fields. i kept getting this error: ChangeConflictException: Row not found or changed
and there was no apparent reason why it was happening, because the same code worked for other tables. I eventually narrowed it down to the only difference between the two tables, a non nullable datetime field. changing this field to nullable removed the problem. this thread
was useful in troubleshooting the problem.
i also found that calling DataBind() on the LinqDataSource before re-binding the GridView helped get rid of this error message.